中文摘要：

利用13对AFLP引物对杨属4个派19个种及杂种的47个无性系进行分析，共检测到858个标记，其中多态性标记为771个，多态性位点的百分率为89．9％，每对引物产生的多态性位点的百分率在80．7％。98．1％之间。表明杨属种间及无性系间在DNA水平上存在广泛变异。根据AFLP标记结果计算杨属派间、派内种间、种内无性系间分子遗传距离，对它们的亲缘关系进行定量描述。聚类分析结果表明，派间聚类与经典形态分类完全一致，派内种间及种内无性系间聚类与形态分类基本相同。最后，探讨根据分子标记结果进行杂交亲本选配及杂种子代早期选择的可行性。

英文摘要：

Thirteen pairs of AFLP primers were screened out and used for the analysis of forty-seven clones, which came from nineteen species and hybrids of four sections in Populus. Thirteen pairs of AFLP primers generated 858 fragments, 771 polymorphism fragments among them. Percentage of polymorphism fragments produced by each pair of AFLP primer was 89.9% in average, and varied from 80.7 % to 98.1%. All these data indicated that considerable genetic variation existed among species and clones at DNA level. Molecular genetic distances among sections, species intrasections, clones intraspecies were calculated, and the relationship among them was described quantitatively. Compared with the classical taxonomy, the result of cluster analysis among sections was consistent completely, and the results of cluster analysis among species intrasections and clones intraspecies were basically similar. Finally, the feasibility of selecting and mating parents and early selection of progenies was discussed based on the results of molecular markers.